Locking ring

ABSTRACT

The invention relates to a locking ring for axially fixing a shaft part ( 3 ) in a ring part ( 1 ). The locking ring ( 5 ) has first partial areas ( 56, 57, 51, 53 ) which engage in the inner groove ( 21 ) after resiliently pressing together the locking ring ( 5 ) so that it can be placed in the inner opening ( 21 ) of the ring part ( 1 ), pushing the safety ring ( 5 ) into the area of the inner groove ( 4 ) and releasing and resiliently placing the locking ring ( 5 ). The locking ring also has second partial areas ( 52, 54, 55 ) that project from the inner groove ( 21 ) once the safety ring ( 5 ) has been placed in the inner groove ( 21 ) and which are resiliently pushed outward in a phase ( 7 ) of the shaft part ( 3 ) which has been pushed into the inner opening ( 2 ) so that the safety ring ( 5 ) can slide on the periphery of the shaft part ( 3 ) until it reaches the area of the peripheral groove ( 4 ) and the second partial areas ( 52, 54, 55 ) resiliently snap onto said peripheral groove.

This is a nationalization of PCT/DE2004/000650 filed 29 Mar. 2004 andpublished in German.

The present invention relates to a locking ring according to thepreamble of main claim 1.

Locking rings of such type are well-known. For example, the patentspecification DE 41 09 481 C2 describes a circlip that has an annularhole for resiliently slipping into an inner groove that has a slopingside or for turning into an inner hole of a ring part. An outer groovewith radial clearance is mounted on a pin, especially for axiallysecuring a releasable serrated connection between the ring part and thepin. For the purpose of mounting, the circlip is bent up and pushed onthe pin till it engages in its outer groove. Subsequently, the pin withthe mounted circlip is inserted into the inner opening of the ring partthat is provided with sloping ends, where the circlip is pressedtogether and expands radially on reaching the inner groove of the ringpart, in order to interlock the pin and the ring part axially.

A problem of such a type of circlip is that it is not centered ideallyafter being mounted on the pin in its outer groove. Consequently, theinsertion of the circlip into the ring part is disadvantageous because alarge phase and/or sloping ends of the ring part are required forinserting the pin with the mounted circlip in the inner opening of thering part or a special servomechanism is necessary for this purpose.

Therefore the objective of the present invention is to create a lockingring that is centered comparatively more precisely in the inner grooveof the ring part even before joining the connection between the shaftpart and a disk part or ring part, so that when inserting the shaft partto be attached to the ring part, an easily reproducible force developsfor opening the locking ring on a phase of the shaft part.

This objective is solved by a locking ring having the characteristicsspecified in the claim 1.

The essential advantage of the present locking ring is that whenestablishing a connection between a shaft part and the ring part, a veryeasily reproducible force develops for opening the ring in the region ofthe sloping ends and/or the phase of the shaft part. Thus, it ispossible to easily record and demonstrate the secure engaging of thelocking ring by monitoring the force during the process of mounting. Thepresent locking ring can be created advantageously such that there areno problems related to imbalance during its use even at a high number ofrotations.

It is of particular significance and advantage that the end areas on theopening and/or partition of the locking ring according to the presentinvention are arranged in the inner groove of the ring part after thelocking ring expands. As a result, these end areas cannot be displacedaxially particularly when inserting the shaft part.

Advantageously, no special servomechanism is necessary when creating theconnection between the shaft part and the ring part.

In a preferred embodiment of the present invention, the inner groove ofthe shaft part is beveled obliquely on at least one side, so that it ispossible to release the connection between the shaft part and the ringpart by applying a sufficiently high axial force. As opposed to that, incase of sharp-edged inner grooves of the shaft part, the connectionbetween the shaft part and the ring part can be released only byforcibly shearing off the locking ring.

The present locking ring can have a triangular or rectangular, oval orelliptical material cross-section, where it is particularly advantageousif the locking ring enters as evenly as possible over the periphery ofthe shaft part for being placed in the inner opening, once the shaftpart is inserted into the ring part, in the groove of which the lockingring is inserted.

Preferred embodiments of the present invention are specified in thecharacteristics of the dependent claims.

The present invention and its embodiments are explained more elaboratelyin the following description on the basis of the figures, of which:

FIG. 1: illustrates a cross-section of the mounted, locking ringaccording to the invention. Said locking ring creates a connectionbetween a shaft part and a ring part;

FIGS. 2 a and 2 b illustrate the cross-section of the ring part as wellas the cross-section of the locking ring that is spirally pressedtogether for insertion into the inner groove of the ring part;

FIGS. 3 a and 3 b illustrate the cross-section of the ring part and across-section of the locking ring according to the invention that isinserted into the inner groove of the ring part;

FIGS. 4 a and 4 b illustrate the cross-section of the ring part as wellas the shaft part which is inserted straight into the inner opening ofthe ring part and/or the cross-section of the locking ring according tothe invention, which is widened on the phase of the shaft part;

FIG. 5 illustrates the cross-section of the ring part and of the shaftpart connected to it; and

FIGS. 6 to 8 illustrate additional embodiments of the invention.

An annular ring part is marked with 1 in FIG. 1. The shaft part and thepresent locking ring are marked with 3 and 5 respectively.

The annular ring part 1 comprises a circular inner opening 2, in whichan annular inner groove 21 is arranged. An annular outer peripheralgroove 41 is arranged in the outer periphery 4 of the shaft part 3.

According to a preferred embodiment, the locking ring 5 essentiallycomprises a base part 52 and lateral side parts 54, 55, that arearranged in it and that have a triangular shape together, wherepreferably the opposite free ends 57 and 58 of the side parts 54, 55 arelocated with a gap between each other in the peripheral direction. Thebase part 52 is connected to the side part 54 using a preferably roundedcorner area 53. Accordingly, the base part 52 is connected to the sidepart 55 using a preferably rounded corner area 51. The shape correspondspreferably to an equilateral triangle, where the end areas 56, 57 arearranged in the area of the third corner.

FIG. 1 illustrates the mounted state of the present locking ring 5, inwhich at least the corner areas 51, 53 and the corner areas 56, 57engage in the inner groove 21 of the ring part 1 and at least the middleareas of the base part 53 and of the side parts 54 and 55 engage in theperipheral groove 41 of the shaft part 3 in order to interlock the ringpart 1 and the shaft part 3, so that they are fixed to one another inthe axial direction against radial movements.

The assembly steps for connecting the ring part 1 with the shaft part 3are explained more elaborately in the following description on the basisof the FIGS. 2 to 4.

First, before the shaft part 3 is inserted into the ring part 1 of thelocking ring 5, the base part 52 and the side parts 54 and 55 of thelatter are pressed together preferably in a linear and spiral manneraccording to FIG. 2 b so that its outer diameter Da is smaller than theinner diameter Di of the inner opening 2 of the ring part 1.Subsequently, the thus pressed locking ring 5 is pushed into the ringpart 1 in the axial direction so far till it reaches the area of theinner groove 21. The locking ring 5 is then released, so that it snapsresiliently with its corner areas 51, 53 and the corner areas 56, 57onto the base wall 22 of the inner groove 21. This state is illustratedin the FIGS. 3 a and 3 b, where in FIG. 3 b, the location of the lockingring 5 is marked by the cross-section II-II in the FIG. 3 a.

According to FIG. 4, the shaft part 3 is inserted into the inner opening2 of the ring part 1, where the shaft part 3 has a phase 7 and/orsloping area on its front end as seen from the direction of insertion.This phase 7 engages in the inner area of the locking ring 5 and expandsit during the continued insertion of the shaft part 3 in the inneropening 2 due to the constantly increasingly diameter of the phase 7,till it snaps resiliently against the outer periphery 4 of the shaftpart 3. A state in which the locking ring 5 is expanded on the phase 7is illustrated in FIG. 4 b.

The shaft part 3 is now pushed so far in the direction of insertion,till the peripheral groove 41 reaches into the area of the inner groove21 and of the locking ring 5 arranged in it, where the areas of thelocking ring 5 lying against the outer periphery of the shaft part 3(particularly the middle areas of the base part 51 and the side parts54, 55) resiliently snap onto the inner groove 21 in order to lock theshaft part 3 on the ring part 1 and the side parts 54, 55 deformedoutward in a bow shape illustrated in FIG. 1 and the base part 52 lockresiliently at the base of the peripheral groove 41 of the shaft part 3and the corner areas 51, 53 and the end areas 56, 57 lock resiliently atbase 22 of the inner grove 21 of the ring part 1.

In the following description the locking ring has a triangular shape.However, even other forms, for example oval or elliptical or polygonalshapes are also feasible, whereby it depends on whether the part areas(preferably rounded corner areas) of the locking ring rest against thebase of the inner groove 21 of the ring part 1 and other partial areas(preferably areas between the corner areas) rest against the base of theinner groove 21 of the shaft part 3 in the mounted state of the lockingring. In the design forms of the locking ring that are particularlypreferred the said resting points of the part areas are distributed asevenly as possible around the inner periphery of the inner groove 41and/or of the peripheral groove 21.

FIG. 6 illustrates an additional embodiment of the present invention inwhich the peripheral groove 41 of the shaft part 3 has two side walls 23that extend obliquely in the axial direction so that it is possible todetach the created connection between the ring part 1 and the shaft part3 by applying an appropriate force in both the axial directions, wherethe locking ring 5 is expanded on an obliquely extending side wall 23 insuch a manner that its partial areas engaging in the inner groove 21project from the inner groove 21. One or two corresponding, obliquesidewalls can also be provided on the peripheral groove 41 in order topress out the partial areas of the locking ring 5 out of the peripheralgroove 41 when pressure is applied in the axial direction.

FIG. 7 illustrates schematically additional preferred embodiments of thepresent locking ring 5′ and 5″ having a quadratic and/or a pentagonalshape. Polygonal shapes with more than four or five corners are alsofeasible.

FIG. 8 illustrates a locking ring 5′″ with an oval form. An ellipticalshape is also feasible.

It is of particular significance in connection with the presentinvention that the corner areas of the safety ring 5, 5′, 5″, 5′″ areeach placed in the area of the opening and/or partition of the lockingring 5, 5′, 5″, 5′″ and that the opening and/or partition is present atthe largest diameter of the locking ring 5, 5′, 5″, 5′″. In this way itis ensured that the end areas 56, 57, 56′, 57′, 56″, 57″, 56′″, 57′″ ofthe locking ring 5, 5′, 5″, 5′″ are arranged after the insertion of thelocking ring into the ring part 1 and after the displacement to theinner groove 21 of the ring part 1 as well as after the expansion of thelocking ring 5, 5′, 5″, 5′″ in the inner groove 21 of the ring part 1.By this arrangement of the end areas 56, 57, 56′, 57′, 56″, 57″, 56′″,57′″ in the inner groove 21, during the mounting steps when insertingthe shaft part 3 and even thereafter in the mounted state, the end areas56, 57, 56′, 57′, 56″, 57″, 56′″, 57′″, which preferably are resilientlysupported, are prevented from being moved and/or pushed to the base wall22 of the inner groove 21 of the ring part 1. Thus a particularly goodaxial fixing of the locking ring 5, 5′, 5″, 5′″ on the ring part 1 isachieved. The corner areas 51, 53, 51′, 52′, 53′, 51″, 52″, 53″, 54″,55″ of the described embodiments of the FIGS. 1, 7 and 8 also engageresiliently in the mounted state in the inner groove 21 of the ring part1. The middle areas lying between two corner areas and/or between twoareas of the largest diameter each engage in the outer groove 41 of theshaft part 3 resiliently in order to fix the shaft part axially and inrelation to the ring part 1.

1. Locking ring for axially fixing a shaft part (3) in a ring part (1),where the shaft part (3) has an peripheral groove (41) and the ring part(1) has an inner groove (21), in which the locking ring (5) comprisingan opening in the circumferential direction engages in the fixed state,characterized in that the locking ring (5) has first partial areas(56.57, 51,53), that engage in the inner groove (21) after theresiliently pressing together the locking ring (5), so that so that itcan be placed in the inner opening (21) of the ring part (1), pushingthe locking ring (5) into the area of the inner groove (21) andreleasing and expanding the locking ring (5) and also has second partialareas (52, 54, 55) that project from the inner groove (21) once thelocking ring (5) has been placed in the inner groove (21) and which areresiliently pushed outward in a phase (7) of the shaft part (3) whichhas been pushed into the inner opening (2) so that the safety ring (5)can slide on the periphery of the shaft part (3) until it reaches thearea of the peripheral groove (41) and the second partial areas (52, 54,55) resiliently snap onto said peripheral groove.
 2. Locking ringpursuant to claim 1, characterized in that, the first and second partialareas are each distributed evenly over the periphery of the inner groove(21) and/or the peripheral groove (41).
 3. Locking ring pursuant toclaim 1, characterized in that, it has the shape of a triangle formedfrom a base part (52) and two side parts (54, 55) connected to theformer, where the first partial areas are formed by the two corner areas(51, 53) between the base part and the side parts and the free end areas(56, 57) of the side parts of the triangle and the second partial areasare formed by the middle areas of the base part (52) and the side parts(54, 55).
 4. Locking ring pursuant to claim 3, characterized in that,the side parts (54, 55) and the base part (52) form an equilateraltriangle.
 5. Locking ring pursuant to claim 1, characterized in that, ithas the shape of a triangle (5′; 5″) with side parts and corner areas,where the first partial areas are formed by the corner areas (51′, 52′,53′; 51″, 52″, 53″, 54″, 55″) and the free end areas (56′, 57′; 56″,57″) adjoining the opening of the locking ring (5′; 5″) and where thesecond partial areas are formed by the middle areas of the side parts ofthe triangle.
 6. Locking ring pursuant to claim 1, characterized inthat, it has an oval or elliptical shape, where the first partial areasare formed by areas of the largest diameter of the locking ring (5′″),where the opening and the end areas (56′″, 57′″) of the locking ring arearranged in an area of the largest diameter of the locking ring (5′″)and where the second partial areas are formed by their middle areas ofthe locking ring (5′″) that lie between the areas of the largestdiameter.
 7. Locking ring pursuant to claim 1, characterized in that,the corner areas (51, 53) are rounded off.
 8. Locking ring pursuant toclaim 7, characterized in that, the rounding of the corner areas (51,53) is adjusted to the radius of the base (22) of the inner groove (21).9. Locking ring pursuant to claim 1, characterized in that, it has acircular, oval, rectangular, quadratic or polygonal design in itsmaterial cross-section.